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Guide 09

The real comparison is total cost, not monthly payment

Whether you are financing solar, a roof replacement, or both — the right comparison is total paid over the life of the project, monthly obligation, break-even timing, and flexibility if your plans change. The advertised monthly payment is only one piece of the picture, and it is often the most misleading one.

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Snapshot
Focus
Payment and ownership structure
Reading time
10 min
Primary risk
Hidden financing cost

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How financing can mislead

A low monthly payment can still hide an expensive project. Here is how it works in practice. A solar system has a cash price of $24,000. Financed through a solar-specific lender with a 25-year term and embedded dealer fees of 25 percent, the actual loan amount becomes $30,000. At a 5 percent interest rate over 25 years, the monthly payment is roughly $175 — which the installer compares to your $200 electric bill. It sounds like savings. But total paid over the life of that loan is approximately $52,500. The same system bought in cash for $24,000 — less the $2,500 Austin Energy rebate bringing the out-of-pocket cost to $21,500 — starts generating bill credits immediately. The financed version does not break even until year 12 or later, and the total lifetime cost is more than double the cash price. This does not mean financing is always wrong. Preserving cash for other priorities has real value, and not every homeowner can or should write a $24,000 check. But the homeowner should know what financing costs them — in real dollars, over real time — and make that choice with full visibility. The same dynamics apply to roofing projects, where financing terms and fee structures can vary just as widely. Start with the issue in front of you. Get clear on the next step.

What to compare between cash and financing

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01

Total paid over the life of the project

This is the clearest single number for understanding whether financing is helping or quietly inflating the cost. Ask for it. If the financed total is 50 to 100 percent more than the cash price, that gap is the cost of financing — and the homeowner should decide whether that tradeoff is worth the monthly payment convenience.

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02

Dealer fees embedded in the financed price

Many solar-specific loans include dealer fees — sometimes called origination fees or channel fees — of 15 to 30 percent. These are added to the loan balance before interest, which means you pay interest on the fee itself over the life of the loan. A $24,000 system with a 25 percent dealer fee becomes a $30,000 loan. Compare the cash price to the financed amount — if there is a significant gap, dealer fees are in play.

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03

Re-amortization assumptions in the loan structure

Some solar loans were originally structured around a large early paydown within 12 to 18 months, and some lenders and loan products still carry re-amortization terms. If the loan assumes a large early payment that is no longer realistic, the monthly payment shown in the proposal may be lower than what you will actually pay. Ask whether the loan terms assume any lump-sum payment and what the monthly number is without it.

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04

Early payoff and exit flexibility

What happens if you sell the home, refinance the mortgage, or want to pay off the system early? Some solar loans have prepayment penalties. Others allow flexible payoff but keep the dealer fee embedded. For roofing financing, similar questions apply around lien structure and transfer options. Understanding your exit options before signing prevents surprises later.

Total cost comparison

What you actually pay: cash vs. financed over 25 years

Same $24,000 system, two paths. The cash buyer is done paying by day one. The financed buyer keeps paying for 25 years — and the gap between the two lines is the real cost of financing.

Same 8 kW system — two payment paths

Questions that make financing offers easier to compare

1
Request the same plan under cash and financed pricing

Keep the equipment and work plan identical so you can see exactly what the financing adds in cost. If the installer only presents one option, ask for the other. Any reluctance to show the cash price alongside the financed price should raise questions.

2
Ask for the total amount financed — not just the system price

If the loan amount is higher than the cash price, the difference is dealer fees. Ask the installer to confirm the fee percentage and show how it affects total cost over the loan term. This is not a hidden number — it is disclosed in the loan documents — but many homeowners do not look for it until after signing.

3
Ask what happens without the projected early paydown

If the loan assumes a re-amortization event — where a projected lump sum is applied to reduce the balance — ask what the monthly payment is without that assumption. This gives you the worst-case monthly number, which is what you should budget for.

4
Compare the 10-year and 20-year total cost picture

Map out cumulative cost at year 10, year 15, and year 20 for both cash and financed scenarios. Include the electric bill savings in both cases. This shows you exactly when each option breaks even and how much total value each one delivers over the system's life.

Understand the full cost before you commit

We break down cash price, financing terms, and total cost over time so nothing is buried in the fine print.

Learn more about solar installs

Financing questions that belong on every comparison

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